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ANSLibs/QRCode/ThresholdBinarizer.h

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/*
* Copyright 2020 Axel Waggershauser
*/
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include "BinaryBitmap.h"
#include "BitMatrix.h"
#include <cstdint>
namespace ZXing {
class ThresholdBinarizer : public BinaryBitmap
{
const uint8_t _threshold = 0;
public:
ThresholdBinarizer(const ImageView& buffer, uint8_t threshold = 128) : BinaryBitmap(buffer), _threshold(threshold) {}
bool getPatternRow(int row, int rotation, PatternRow& res) const override
{
auto buffer = _buffer.rotated(rotation);
const int stride = buffer.pixStride();
const uint8_t* begin = buffer.data(0, row) + GreenIndex(buffer.format());
const uint8_t* end = begin + buffer.width() * stride;
auto* lastPos = begin;
bool lastVal = false;
res.clear();
for (const uint8_t* p = begin; p != end; p += stride) {
bool val = *p <= _threshold;
if (val != lastVal) {
res.push_back(narrow_cast<PatternRow::value_type>((p - lastPos) / stride));
lastVal = val;
lastPos = p;
}
}
res.push_back(narrow_cast<PatternRow::value_type>((end - lastPos) / stride));
if (*(end - stride) <= _threshold)
res.push_back(0); // last value is number of white pixels, here 0
return true;
}
std::shared_ptr<const BitMatrix> getBlackMatrix() const override
{
return std::make_shared<const BitMatrix>(binarize(_threshold));
}
};
} // ZXing